Requests of users as to recent power substations have been diversified. That is, for example, in accordance with intended uses of customers of a power substation, types of loads and operating conditions differ from each other. Therefore, a distribution system is planned in consideration of safety, reliability, and operation maintainability required by customers, and increase of future load. In the distribution plan, control of a breaker, a disconnector, an earth switch, and the like forming the power substation, and monitoring and instrumentation of voltage, current, electrical power, and the like, need to be considered in accordance with needs of customers.
In this case, consideration of how to reduce installation spaces for the above mentioned devices such as the breaker, the disconnector, the earth switch and the like, controllers for the devices, and monitoring measurement hardware has been needed to suppress investment for the installation. In addition to this need, there are also further needed considerations such as removal of a faulty section at the site when part of the equipment should be out of order, ease of recovery operation including changing parts, and quickness of the recovery operation including power supply recovery.
In order to cope with these needs, there is provided a vacuum insulated switchgear comprising a vacuum double-break three-position type switch having breaking and disconnecting functions. A switch section having the switch and an operation device therein constitutes a unit separable from a housing of the vacuum insulated switchgear. The unitized switch section is selectively connected to and disconnected from a bus in a bus section and is movably provided in the housing (see, for example, JP-A-2008-245409).
For example, in the case of the power substation in which vacuum insulated switchgears constitute panels in parallel rows thereof, even if a fault occurs at one of the panels supplying power to an external load, its recovery operation is completed by replacing the switch section of the faulty panel with a backup switch section. Therefore, it becomes possible to recover the power supply for the entire power substation after a short interruption period.
However, for example, when the above substitute (backup) switch section is not prepared by a user or, even if it is prepared, when the faulty section of the panel includes a bus, even in the case of the above vacuum insulated switchgear, it may be difficult to recover the power supply of the entire power substation in a short time. The reason is that, in the power substation in which plural vacuum insulated switchgears arranged as panels in parallel rows, a bus of each panel (vacuum insulated switch gear) since is connected to an adjacent panel, in order to isolate the faulty section one of the panels from faultless other panels, an operation is required at a bus portion of the other panel or panels adjacent to the faulty panel.
When recovering the power supply of the entire power substation, a vacuum insulated switchgear is needed to enable recovery after a short interruption time even in the case where the recovery operation is also needed at the bus portion of the other panel adjacent to the faulty panel.
The present invention was made in view of the above mentioned-needs, and its object is to provide a vacuum insulated switchgear capable of being reduced in size and weight, reliable, and which enhances quick recovery of the entire facility when a fault occurs.